Ressource Stadt: City as Resource - One Man's Trash is Another Man's Treasure By Folke Köbberling and Martin Kaltwasser. Jovis, 2006. 128pp. £14.99
'For us', write artists Folke Köbberling and Martin Kaltwasser, 'true luxury is when we built a house out of waste materials overnight in a field and spent a week living there.'
Those concerned for the couple's sanity will not have their fears allayed when they learn that they took their two young children with them.
'People thought we had become homeless, ' they say cheerfully.
Köbberling and Kaltwasser have devoted themselves - and their family life - to the recycling and reuse of waste material to create temporary shelters and installations in city settings. Their work has grown organically from the Berlin squatter scene, and although dogmatic, their argument in favour of a deregulated, heterogeneous urban environment is a compelling one - even if its logical conclusion would be shantytowns in Schöneberg.
Unfortunately, the rather inconsistent work the couple creates doesn't quite stand up to their enthusiastic theorising.
Hausbau 04 and Hausbau 05, both in Berlin, look shabby and, frankly, uninhabitable.
The Berlin Musterhaus, on the other hand, is bright, cosy and communal, while the accomplished Haus Köln (see picture), constructed with the aid of sculptor Christian Maier, is a perky neighbour to Cologne's medieval Stapelhaus.
Köbberling and Kaltwasser's evident passion dispels any potential accusations of dilettantism, and the couple have produced a persuasive antidote to the mundane hi-tech uniformity of modern cities.